1. Field of the Invention
The present invention relates generally to wheel rims and, more specifically, to a wheel rim that has a top cover to provide added strength to the wheel rim.
2. Background of the Art
Wheel rims made from rolled and welded steel or aluminum are common. Sheet stock of the metal is cut in a generally rectangular shape to the appropriate length and width dimensions. The metal blank is then formed into a closed circle and the formerly opposing ends are butt welded together. The metal circle or tube is then roll-formed to create the desired profile of the wheel rim for retaining the tire, any inner tube, anchoring spokes if used, and the like. Because the wheel rim is formed of a single sheet, the strength of the wheel rim is determined largely from the thickness of the metal selected for use in the manufacture of the wheel. While heavier stock can be used to increase the strength of the wheel rim, forming of the heavier material may require different, stronger machines and tools at a significantly higher cost. There is a need, accordingly, for a roll-formed wheel rim that has added strength without using a heavier stock of material and that can be manufactured using standard roll-forming machines and tools.